| Tri-Core | |
| Tri-County Communications, Inc. | New York |
| Tri-County Electronics | Wisconsin |
| Tri-County Technical College | South Carolina |
| Tri-County Web Consulting | |
| Tri-Data, Inc. | West Virginia |
| Tri-Delta Resources | New York |
| Tri-Force Consulting Services, Inc. | Pennsylvania |
| Tri-Global Technologies, LLC | Georgia |
| Tri-Lakes Internet, LLC | Missouri |
| Tri-Mag, LLC | California |
| Tri-Pac Indiana, Inc. | |
| Tri-Pacific Software, Inc. | California |
| Tri-Star Telecommunications | California |
| Tri-State Business Systems, LLC | New Jersey |
| Tri-State Computer Services | Arizona |
| Tri-State Electronic Corporation | Illinois |
| Tri-State Visual Products | Ohio |
| Tri-Tec Communications, Inc. | Washington |
| Tri-Tronics Co., Inc. | Florida |
| TRIAD | Ohio |
| Triad Hosting, Inc. | North Carolina |
| Triad Media, Inc. | Nevada |
| Triad Spectrum, Inc. | Texas |
| Triad Telecom, Inc. | North Carolina |
| Triada Networks, LLC | New Jersey |
| Triadic Software | Kentucky |
| TriaFederal | |
| Triagons | Delaware |
| Trial Runners | North Dakota |
| TriAltus Bioscience | Alabama |
| TRIANA Biomedicines, Inc. | Massachusetts |
| Triangle | New York |
| Triangle Biotechnology, Inc. | |
| Triangle Cloud Services | Pennsylvania |
| Triangle CompuDocs, LLC | North Carolina |
| Triangle Direct Media | North Carolina |
| Triangle Linux Users Group | North Carolina |
| Triangle MicroWorks, Inc. | North Carolina |
| Triangle Solutions Technology | North Carolina |
| Triangle Systems, Inc. | |
| TrianglZ, LLC | |
| Triare, LLC | |
| Triares, Inc. | |
| TriArm Therapeutics | |
| TriAxial Medical, Inc. | Florida |
| Triaxiom Security, LLC | North Carolina |
| Tribal Core | California |
| Tribal Pictures | Georgia |
| Tribal Software | Wyoming |